I love this carrier. I used to recommend the Hippy Chick, a similar British version, when I was working as a chiropractor overseas. In this country, I've been sending folks to ebay to get the Korean version of it, but SO so glad to see this selling in this country.
I find it fabulous for your spine if you wear it well. I suggest wearing so the child is on one hip of the other, with the strap firmly settled on the hips. It keeps you from throwing one hip out to the side to hold the child, and keeps you from holding up their weight with one arm, as it settles the weight across your pelvis. But if you wear it in the front, it tends to over-accentuate the curve of your lumbar or lower spine, and that can cause some problems, especially if relaxin, a pregnancy hormone, is still at play, which it can be if you are still breast feeding.
The above poster thought the Ergo was a better call, and I agree, the Ergo is a fabulous carrier and a better choice for a child or a situation where the kid will joyfully stay in the sling. This design, however, is great if you have a child who wants up. No, down. No, up. No, down.... and so on. I used it a lot around the house and on long long flights, when wrestling my son in and out of a sling was more unrealistic. Properly used, I think it reduces the twisting of your spine.
Triple thumbs up from the perinatal/pediatric chiropractor.